Manufacturers and marketers of hydrocarbon lubricating oils are packaging increasingly larger percentages of their hydrocarbon lubricating oils in widemouth cylindrical containers fabricated from high density ethylene polymers. This shift in packaging of such hydrocarbon lubricating oils has resulted from the fact that such plastic containers can be fabricated at significantly lower cost than the metal containers previously used for this purpose. One of the shortcomings associated with the use of such plastic containers is that the filled containers, particularly when exposed to sunlight over extended periods of time, frequently will develop inwardly-directed bulges. This phenomenon has been characterized in the art as "panelling."